Tear strip opener with venting means



Sept. 17, 1968 w. E. TAYLOR TEAR STRIP OPENER WITH VENTING MEANS Filed June 26, 1964 W. MOA m M M M w I. ?IIIIIIIIIJ.IA

Affi/94(5)( United States Patent O 3,401,820 TEAR STRIP OPENER WITH VENTING MEANS William Edward Taylor, Fairfield, Conn., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed June 26, 1964, Ser. No. 378,142 17 Claims. (Cl. 220--54) The present invention relates generally to a container having a rip strip formed in an end thereof and more particularly to the provision in such a container of means which prevent the particles of a gas generating product from being ejected from the container when it is initially opened because of the positive gas pressure therein.

At the present time, the packing of gas generating products such as ground coffee in easy-opening cans having a rip strip formed in their top ends is being seriously considered. In order to prevent deterioration of the product through oxidation, the filled can must normally be initially closed under vacuum to exclude air therefrom. The product in the can, however, generates a gas, which in the case of ground coffee is carbon dioxide, which soon dissipates the vacuum and develops a positive pressure within the sealed can. When the can is thereafter broken open by the consumer to free the lead end of the rip strip, the initial surge of this pressured gas through the small initial opening thus formed causes some of the product particles to be forcibly ejected from the can and to be sprayed over an area extending several feet from the can. This situation is intolerable commercially, since it is wasteful of the product and annoying to the user.

In order to eliminate this problem of the unwanted ejection of the coffee particles from the can when it is initially opened, the present invention contemplates the use of a gas permeable membrane which is positioned between the gas generating product and the area of initial opening of the container. This membrane is made of a material which has the property of permitting the gas evolved by the coffee to pass freely through it, but of restraining such passage of the ground coffee particles. By reason of its construction, the membrane thus functions to permit the venting of the positive gas pressure from the container when it is initially opened and to prevent the product particles from being ejected from the can during the venting of the positive gas pressure therein.

An object of the present invention, therefore, is to provide a novel rip strip container for packaging a gas generating product such as ground coffee.

Another object is the provision of such a container which permits the venting of the positive gas pressure therein when the container is initially opened and which prevents the product particles from being ejected from the can during the opening thereof because of this positive pressure.

A further object is to provide such a container wherein a gas permeable membrane is positioned between the point of initial opening of the rip strip and the product, the membrane being so constructed as to allow the venting of the positive gas pressure therethrough while preventing the product particles from passing therethrough.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawing, discloses a preferred embodiment thereof.

Referring to the drawing:

FIGURE l is a plan view, with parts broken away, of the top end of a container constructed in accordance with the principles of the instant invention;

FIG. 2 is an enlarged sectional view taken substantially along line 2-2 in FIG. l, showing the top end portion of the container;

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FIG. 3 is an enlarged view of a portion of the container shown in FIG. 2, showing the end closure of the container as it is being initially opened;

FIG. 4 is a plan view of the top end of a modified form of the container; and

FIG. 5 is an enlarged sectional View taken substantially along line 5 5 in FIG. 4, showing the top end portion of the modified container.

As a preferred or exemplary embodiment of the instant invention, FIGS. l and 2 disclose a container 10 for packaging a gas generating product 12, such as ground coffee. The container 10 comprises a generally cylindrical body 14 formed of sheet metal which is closed at its lower end (not shown) in any suitable or conventional manner, such as by an end closure double-seamed thereto or by an integral end panel.

The upper end of the container body 14 is closed by an end closure 16 preferably formed of sheet metal which is secured thereto in a conventional, hermetic double seam 18. The end closure 16 comprises an annular countersink wall 20 and a generally flat central panel 22 (see FIG. 2). A first score line 24 is formed in the central panel 22 and extends completely therearound in closely adjacent relation to the countersink wall 20. A second curved score line 26 extends inwardly from the score line 24 at a point 25 and is directed generally towards the center of the end panel 22 (see FIG. l). A third score line 28 formed in the end panel 22 begins at a point 30 disposed radially inwardly of the score line 24 and extends from the point 30 around the end panel 22 in substantially parallel relation to the first score line 24 and then towards the center of the end panel 22 in substantially parallel relation to the second score line 26. The score line 28 merges with the score line 26 approximately at the center of the central panel 22 in a curved score line 32. The score lines 24, 26, 28 and 32, therefore, define a removable rip strip section 34 in the end panel 22 which extends from the center thereof in a curved path substantially radially outwardly to the periphery of the end panel 22 and substantially completely therearound.

Secured to the removable section 34 at its innermost end adjacent the curved score line 32, is a substantially rigid, generally flat lift-tab or opening lever 36. The lever 36 is punched or cut from a strip of flat metal stock and, to increase its rigidity, there are formed therein a plurality of longitudinally extending reinforcing ribs -or embossments 38. The lever 36 is secured at its innermost end to the removable area 34 by a peened-over embossment or rivet 40 which is integral with and drawn from the central panel 22, the rivet 40 extending upwardly through an aperture in the innermost end of the lever 36 'and having its upper end peened outwardly to secure the lever 36 in place. The outer or free end 42 of the lever 36 is upturned slightly away from the adjacent panel 22, thereby allowing the fingertip of the consumer to be readily inserted under the free end 42 of -the lever for the purpose of opening the container.

As shown in FIGS. l and 2, a permeable membrane or diaphragm 44 of circular shape is interposed between the granular product 12 and the central panel 22 of the end closure 16. The membrane 44 preferably is lformed of a loosely woven fibrous material, such as hemp paper, having a natural porosity created by the interstices between its fibers. It is obvious, however, that the membrane 44 could also be formed of a normally non-porous material, such as metal foil or dense paper or cardboard, which is made permeable to gas by being provided with a plurality of perforations which permit passage of the gas but which are suiciently small to enable the membrane to act as a barrier to prevent the granular product within the container from passing therethrough.

Referring now to FIG. 3, when the consumer opens the container 10 by pulling upwardly on the outer or free end 42 of the pull tab or lever 36 to fracture the central panel 22 along the circular score line 32, the gas pressure within the container 10 is vented through the permeable membrane 44 and the opening 46 formed in the central panel 22. The membrane 44 is urged against the undersurface of the central panel 22 by the outward surge of the gas and coffee particles when the hermetic seal of the can is thus broken, but since the membrane will not permit the passage of the granular product therethrough, it prevents the granular product from being carried through the opening 46 in the end panel 22 by the outrushing gas when the end closure is initially opened by the consumer. The membrane 44, therefore, serves to prevent the loss of any coffee or granular product 12 within the container 10 during the opening thereof, without interfering with the venting of the gas pressure within the container.

FIGS. 4 and 5 illustrate a modified form of gas permeable membrane which is in the form of a patch 144 of circular or any other suitable shape which is adhesively secured to the underside of the central panel 22 in any suitable manner, as by spaced spots of adhesive (not shown) spaced outwardly around the score line 32. The patch 144 is of sutlicient size to extend beneath the point of initial opening in the central panel 22, thereby serving to vent the positive gas pressure in the container 1) and to prevent the granular product 12 therewithin from being exhausted through the opening during the venting of the gas pressure. This modified construction is advantageous in that, during the opening of the container, the membrane patch 144 is removed from the container body 14 with the central panel 22 of the end closure 16, since it is adhesively secured thereto.

It will be -obvious that various other modifications of the instant invention can be made while still preserving the essential concept of retaining the solid product particles in the can by means of a porous material which permits escape of the pressurized gas during the opening operation. As examples of such other modifications, the disc or membrane 44, which in FIGS. 1 and 2 is shown as being loosely interposed between the product 12 and the end member 16 so that it can be dropped into the can before or after it is filled, depending on which end member is seamed to the can prior to its being filled, may be increased in diameter so that it frictionally engages the can body wall 14 so that it can be held in place in the empty can while the latter is being shipped from the can manufacturer to the coffee packer. It might be desirable in such cases to bend the marginal edge portion of the oversized disc membrane in a direction away from or towards the end member 16 in order to form it with a flange which engages the can body wall 14 with increased frictional contact. In either event, the end member 16 would of course be seamed to the body by the can maker and the bottom end member would be attached in the coffee packing plant.

It might also be desirable to provide the container of the instant invention with a reclosure to protect its contents in the event they are not completely used up at the time of opening. Such reclosure might take the form of a molded plastic snap-on overcap which snaps into engagement around the top double seam 18. However, such overcaps are conventionally used on coffee cans, and are not considered to be a part of the instant invention.

It is thought that the invention and many of its attendent advantages will be understood from the `foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

What is claimed is:

1. In a container for a gas generating granular product:

a top end member having a removable section therein,

and

a gas permeable membrane disposed within said container adjacent the point of initial opening of said removable section, said membrane being so constructed as to prevent the passage of the granular product therethrough.

2. A container for a gas generating granular product, comprising:

a container body,

an end closure hermetically sealed to one end of said container body,

a scored removable section formed in said end closure,

and

a gas permeable membrane disposed Within said container body adjacent the point of initial opening of said scored removable section, said membrane being so constructed as to prevent the passage of the granular product therethrough.

3. The container of claim 2 wherein said membrane is of substantially the same width as said container body.

4. The container of claim 2 wherein said membrane is of substantially less width than said container body and is adhesively secured to the undersurface of said end closure.

5. A container, comprising:

a container body,

a gas generating granular product disposed within said container body,

an end closure hermetically seamed to one end of said container body,

scored opening means formed in said end closure, and

a gas permeable membrane disposed within said container body between said end closure and said granular product, said membrane being disposed adjacent the point of initial opening of said scored opening means in said end closure and being so constructed as to prevent the passage of the granular product therethrough and thus the passage of the granular product through the end closure when it is initially opened.

6. The container of claim 5, wherein said membrane is of substantially the same width as said container body.

7. The container of claim 5 wherein said membrane is adhesively secured to the undersurface of said end closure.

8. The container of claim 5 wherein said opening means comprises:

a removable section defined by a plurality of score lines in said end closure, and

a pull tab is secured to said removable section to facilitate the removal thereof from said end closure.

9. The container of claim 8 wherein said removable section extends in a curved path from approximately the center of said end closure toward and around the periphery of said end closure, and wherein said gas permeable membrane is positioned beneath the portion of the removable section which is disposed at the center of said end closure.

10. An end closure for a container adapted to hold a gas generating product, comprising:

a generally at central panel,

opening means for-med in said panel, and

a gas permeable membrane adhesively secured to the undersurface of said panel adjacent the point of initial opening thereof, said membrane being adapted to prevent the passage of the gas generating product therethrough.

11. In an easy opening container, an imperforate panel having a removable tear strip including a starting end, means attached to said tear strip for tearing said tear strip from said panel starting at said starting end, and a layer of porous material connected to said panel in direct underlying relation to said tear strip starting end to prevent the outiiow of a packaged product through an opening formed in said panel along said tear strip starting end during the initial phase of opening the container.

12. The container of claim 11 wherein said porous material is in sheet form and adhesively secured in place.

13. The container of claim 11 wherein said porous material is in sheet form and is formed of paper.

14. An end closure for a container, said end closure having an imperforate end panel of which a portion is to be removed by a tearing action in the opening of an associated container, said removable portion including a tear strip having a starting end which is to be initially separated from the remainder of said end panel and when this initial separation occurs a temporary vent opening will be formed, and a product retainer secured to said end closure and directly underlying said tear strip starting end to cover the vent opening when formed, said product retainer being in the form of a sheet of porous material capable of freely passing gases while retaining solids and liquids.

15. The end closure of claim 14 wherein said sheet of porous Imaterial is formed of paper.

16. The end closure of claim 14 wherein a sheet of 20 porous material is carried solely by said removable end panel portion for the automatic removal thereof in the opening of an associated container.

17. In an easy opening container an imperforate panel having a removable scored section including a starting end, means attached to said removable scored section for tearing said removable scored section from said panel starting at said starting end, and a layer of porous material disposed within said container in direct underlying relation to said removable scored section starting end to prevent the outflow of a packaged product through an opening formed in said panel along said removable scored section starting end during the initial phase of opening the container.

References Cited UNITED STATES PATENTS 3,077,409 2/1963 Baselt 220-44 3,182,852 5/ 1965 Wilkinson 220-54 3,221,923 12/1965 Bozek 22054 THERON E. CONDON, Primary Examiner.

G. T. HALL, Assistant Examiner. 

1. IN A CONTAINER FOR A GAS GENERATING GRANULAR PRODUCT: A TOP END MEMBER HAVING A REMOVABLE SECTION THEREIN, AND A GAS PERMEABLE MEMBRANE DISPOSED WITHIN SAID CONTAINER ADJACENT THE POINT OF INITIAL OPENING OF SAID REMOVABLE SECTION, SAID MEMBRANE BEING SO CONSTRUCTED AS TO PREVENT THE PASSAGE OF THE GRANULAR PRODUCT THERETHROUGH. 